All the information is locally saved on your own computer. The program is going to keep the Shortcuts that you created and all are going to be displayed on the Main window of the program. What you can do is Back up the data so you would keep all the shortcuts that you create. If you have problems the best that you can do is reinstall the program.
Delete all the cache of the program. Uninstall your software first, then go to the folder location below on your computer then delete the FastFox folders:
C:\ProgramData\NCH Software
C:\Users\(Your computer profile)\AppData\Roaming\NCH Software\FastFox
If you can't find the AppData folder, set Windows to show hidden files and folders with the steps from this link: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files.
After deleting the FastFox folder, restart your computer then install it again from the next link: https://www.nch.com.au/fastfox/ffsetup.exe